BGP Community Controls for I2PX Participants:

Updated for NGI, September 2021.

Per-peer traffic engineering communities:

• 65000:<ASN> Do not advertise at all to the peer ASN
• 65001:<ASN> Prepend once toward peer ASN
• 65002:<ASN> Prepend twice toward peer ASN
• 65003:<ASN> Prepend thrice toward peer ASN
• 65009:<ASN> Allow advertisement toward peer ASN if otherwise excluded by more general community control such as 11164:52000

Remote Triggered Black Hole (RTBH) communities:

The following communities can be used to blackhole traffic to more specific netblocks (up to IPv4 /32 and IPv6 /128).

• 65535:666 Rewrite next hop to discard traffic (RFC7999 well-known community)
• 11164:53666 Rewrite next hop to discard traffic

Set local-pref on I2PX participant routes:

• 11164:51240 Set local-pref high (240) to indicate a preferred route
• default local-pref (220)
• 11164:51200 Set local-pref low (200) to indicate a backup route

These additional communities are available to alter relative preference. Though available, these communities are rarely used and can take substantial care to appreciate the outcome from using them:

• 11164:51080 Set preference of learned route Below standard local preference value for Settlement Free Peers.
• 11164:51050 Set preference of learned route Below standard local preference value for any Transit Providers (no Transit Providers exist to-date).

Additionally, these communities can be used to alter the announcement profile of your routes:

• 11164:52000 Do not export to peers
• 11164:52001 Prepend once to peers
• 11164:52002 Prepend twice to peers
• 11164:52003 Prepend thrice to peers

• 11164:52400 Do not export to North American peers (all I2PX peers to-date)
• 11164:52401 Prepend once to North American peers
• 11164:52402 Prepend twice to North American peers
• 11164:52403 Prepend thrice to North American peers
• 11164:52300 Do not export to Extended Peers

Related communities for future use, but which are in-active in the network, at present:

• 11164:52200 Do not export to transit
• 11164:52201 Prepend once to transit
• 11164:52202 Prepend twice to transit
• 11164:52203 Prepend thrice to transit
• 11164:52500 Do not export via peer-links in Asia-Pac
• 11164:52501 Prepend once via peer-links in Asia-Pac
• 11164:52502 Prepend twice via peer-links in Asia-Pac
• 11164:52503 Prepend thrice via peer-links in Asia-Pac
• 11164:52600 Do not export via peer-links in Europe
• 11164:52601 Prepend once via peer-links in Europe
• 11164:52602 Prepend twice via peer-links in Europe
• 11164:52603 Prepend thrice via peer-links in Europe

Please let us know if you have questions, noc@net.internet2.edu.